*{
    margin: 0;
    padding: 0;
    list-style: none;
}
ul{
    width: 100%;
    height: 80px;
    position: fixed;
    bottom: 0px;
    left: 0px;
}
ul li{
    float: left;
    width: 70px;
    height: 80px;
    margin-left: 20px;
    background: lightyellow;
    text-align: center;
    line-height: 120px;
}
.b1{
    color:lime;
    background: orange;
}
.b2{
    color:red;
}